Fix xytest requires xy.sty to run

Author: brucemiller

t/65_graphics.t

@@ -6,4 +6,5 @@ use LaTeXML::Util::Test;
 
 latexml_tests("t/graphics",
 	      requires=>{colors=>'dvipsnam.def',
-			 xcolors=>'dvipsnam.def'});
+			 xcolors=>'dvipsnam.def',
+                         xytest=>'xy.sty'});